Alpaca API Platform

Alpaca API Platform #

Why API? #

Alpaca’s features to access financial markets are provided primarily via API. We believe API is the means to interact with services such as ours and innovate your business. Our API is designed to fit your needs and we continue to build what you need.

REST, SSE and Websockets #

Our API is primarily built in the REST style. It is a simple and powerful way to integrate with our services.

In addition to the REST API which replies synchronous communication, our API includes asynchronous event API which is based on WebSocket and SSE, or Server-Sent Events. As many types of events occur in the financial markets (orders fill based on the market movement, cash settles after some time, etc), this event-based API helps you get updates instantly and provide the best user experiences to your customers.


The FIX (Financial Information Exchange) protocol for the user API support is on the roadmap. If you have needs for this support, please contact us so that we can assess the priority.

Architecture #

Alpaca’s platform consists of APIs, Web dashboards, trade simulator, sandbox environment, authentication services, order management system, trading routing, back office accounting and clearing system, and all of these components are built in-house from ground up with the modern architecture.

The Alpaca platform is currently hosted on the Google Cloud Platform in the us-east4 region. The site is connected with dedicated fiber lines to a data center in Secaucus, NJ, to cross-connect with various market venues.

Under the hood, Alpaca works with various third parties. We work with Velox Clearing for trade clearing and settlement on DTCC. Cash transfers and custody are primarily provided by First Republic Bank. Citadel Securities, Virtu America, Clearstreet, Wolverine Trading and other execution providers provide execution services for our customer orders. We integrate with ICE Data Services for various kinds of market data.